Treatment of fibers of acetyl cellulose to produce wool-like effects



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RENE CLAVEL, F BASEL-AUGST, NEAR BASEL, SWIfEERLAND.

TREATMENT OF FIBERS OF ACETYL CELLULOSE TO PRODUCE WOOL-LIKE EFFECTS.

No Drawing. Applicationfiled September 27, 1923, Serial No. 665,180, and in France November 9, 1922.

This invention relates to a process for as such or in fabrics consisting wholly or partly thereof.

In dyeingacetyl cellulose threads in acetic or formic acid media, it has been observed that at the raised temperature of the dye baths a woolly effect was produced on the acetyl cellulose artificial silk, which considerably affected the lustre of the goods, that is to say caused a dulling of the fiber.

According to the invention I obtain excellent soft, woolly effects" on yarns. or threads of acetyl cellulose as such or in fabrics consisting of or containing them, by heating said yarns or fabrics with solutions of acetic or formic acid of suitable concentration at about boiling temperature. acids are hereinafter included in the term a low aliphatic acid. The greater the concentration of the acetic acid or formic acid, the greater will be the woolly effect or the increase of volume of the fiber. However, when too great a quantity of the acid, is used, a dissolution of the acetyl cellulose silk may manifest itself, that is to say the fibers may be attacked to such an extent that their strength and elasticity are considerably reduced, so that they are rendered unsuitable for subsequent weaving. It is understood, therefore, that the concentration of the acid employed should be insufficiently high to cause substantial destruction of the fiber- It is moreover advantageous to add protective colloids to the strongly acid baths to prevent or restrain the. too pronounced attack of the fiber by the acids.

Where the word dissolution is used in the specification and claims, it is to be understood that it implies the act of dissolving and all stages thereof, so that it covers all phases of partial solution, as well as complete solution.

It has been further found that the same preventing or restraining effect can be obtained by the employment of suitable salts, in particular salts which are capable of exerting 'a. precipitating effect on the acetyl'celluloses dissolved or partially in solution. These salts may be employed alone or concurrently with the protective colloids.

Of the two acids, preference is given to acetic acid of suitably chosen concentration, because this, at a raised temperature, has a dissolving action on the acetyl cellulose Said and so gives beautiful, very supple or soft feeling woolly effects on threads or yarns or piece goods, of acetyl cellulose.

The process can be applied to cellulose acetate threads or yarns in hanks or fabrics or in mixed fabrics. whether in the. dyed or undyed state. Its employment offers remarkable advantages for mixed fabrics consisting of cellulose acetateartificial silk and various natural or artificial textile materials, where it is desired to obtain woolly or soft dull or matt effects.

E ammple.

ulated with formic acid, to give the desired touch.

\Vhat I claim and desire to secure by Letters Patent is 1. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at about boiling temperature with a solution containing a low aliphatic acid, said acid being in moderate concentration but insufficiently high to cause substantial destruction of the 2. Process for producing soft woolly effects on'threads and yarns of acetyl cellulose comprising treating them at about boiling temperature with a solution containing. a low aliphatic acid and an agent capable of restraining dissolution of the acetyl cellulose by the acid, said acid being in moderate concentration but insufficiently ligh to cause substantial destruction of the er. 3. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at about boiling temperature with a solution contaijn= ing a low aliphatic acid and a protective colloid, said acid being in moderate concentration but insufficiently high to cause substantial destruction of the fiber.

4. Process for producing soft woolly effects I on threads and yarns of acetyl cellulose, comprising treating them at about boiling temperature with a solution containing a low aliphatic acid, a protective colloid and a salt capable of exerting a precipitating acv tion on acetyl cellulose, said acid being in moderate concentration but insufiiciently iiiggh to cause substantial destruction of the er. a

5. Process for producing soft woolly effects on threads and yarns of acetyl cellulose,

comprising treating them at about boiling temperature with a solution containing acetic acid, said acid being in moderate concentration but insufficiently high to cause substantial destruction of the fiber.

6. Process for producing soft woolly effects on threads and yarns of acetyl cellulose,

- comprising treating them at about boiling temperature with a solution containing acetic acid and an agent ca able of restraining dissolution of the acetyl cellulose by the acid, said acid being in moderate concentration but insufficiently high to cause substantial destruction of the fiber.

7. Process for producing soft woolly effects on threads and yarns of acetyl cellulose,

comprising treating them at aboutboiling temperature with a solution containing acetic acid and a protective colloid, said acid being in moderate concentration but insufli- -ciently high to cause substantial destruction of the fiber. I

8. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at about boiling temperature with a solution containing acetic acid, a protective colloid and a salt capable of exerting a precipitating action on acetyl cellulose, said acid being in moderate concentration but insufficiently high to cause substantial destruction of the fiber.

acid 9. Process for producing soft woolly effects on threads and yarns of. acetyl cellulose comprising treating them at about boiling temperature with a solution containing acetic acid in a concentration of about 8 per cent.

10. Process for producing soft woolly effects on threads'and yarns of acetyl cellulose v comprising treating them at aboutboiling temperature with a solution containing acetic. acid in a concentration of about 8 per 'cent temperature with a solution containing acetic acid in a concentration of about 8 per cent, said solution also containing a protective colloid and a salt capable of exerting a precipitating action on acetyl cellulose.

13. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at aboutboiling temperature, with a solution containing a low aliphatic acid in concentration not above about 8%.

14. Process for producing soft woolly effects on threads and yarns ofacetyl cellulose, comprising treating them at'about boiling temperature with a solution containing a low aliphatic acid in concentration not above about 8% and an agent capable of restraining dissolution of the acetyl cellulose by the acid. 7

15. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at boiling temperature with a solution containing a low aliphatic acid in concentration not above about 8% and a protective colloid.

16. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at boiling temperature with a solution containing a low aliphatic acid in concentration not above about 8% and a protective colloid and a 'salt capable of exerting a precipitating action on acetyl cellulose.

17. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at about boiling temperature with a solution containing acetic acid in concentration not above about n 18. Process for producing soft woolly ef-' fects on threads and yarns of acetyl cellulose, comprising treating them at about boiling temperature, with a solution containing acetic acid in concentration not above about8% and an agent capable of restraining dissolution of the acetyl cellulose by the acid. 1

19. Process for producing soft woolly effects on threads and yarns of acetyl cellulose, comprising treating them at about boiling temperature with a solution containing acetic acid in concentration not above about 8% and a protective colloid.

20. Process for producing soft woolly efc fects on threads and yarns of acetyl cellu lose, comprising treating them at about boiling temperature with a-solution containing acetic acid in concentration not above about 8%, and a protective colloid anda'salt capable of exerting a precipitating action on acetyl cellulose. e

In'testimony whereof I have hereunto sub scribed my name.

RENE cIJ vEL. 

